Skip to calculator
Cinder Block Calculator

General masonry

Block Wall Calculator

A general block wall estimator. Use it when you care about face size and openings more than the marketing name of the unit.

Calculator

1

Wall dimensions

Enter length and height. Add more sections for corners or extra walls.

ft
ft

No wall sections calculated yet

2

Block size

Nominal face size includes the mortar joint. Width is the wall thickness.

Face dimensions are the wall face (length × height). Width is how deep the block sits in the wall.

3

Doors & windows

Subtract doors and windows from the wall area for a more accurate block estimate.

No openings yet. Solid walls skip this step.

4

Waste allowance

Extra blocks for cuts, breakage, and layout. Actual waste varies by project — this is an estimate, not a requirement.

5

Mortar & core fill

Optional material estimates. Assumptions are listed with the results.

Mortar

in

Default assumes about 33 standard 8×8×16 in blocks per 80 lb bag with a 3/8 in face-shell joint.

Not every wall has grouted cores. This is a volume estimate only — it does not determine reinforcement or engineering requirements.

6

Cost estimate

Optional. Enter your local prices — this tool does not assume market rates.

Enter your wall dimensions to see your estimate.

The diagram updates as you type.

Your estimate will appear here

Add a wall length and height to calculate blocks, mortar, and optional cost.

Any modular block wall

Block walls are counted the same way whether the unit is labeled cinder block, concrete block, or CMU: net wall area divided by the block face, plus waste. Choose a preset or enter a custom length, height, and width.

When to use this page

Use this calculator if you are comparing unit types, working from a takeoff that just says “block,” or laying out a wall that is not specifically specified as cinder block. The diagram still shows courses and openings so you can sanity-check the count. A block count is not a safety plan: OSHA masonry construction requirements (opens in a new tab) cover limited-access zones and bracing for walls over eight feet.

Looking for the full estimator with wall diagram and openings? Use the cinder block calculator.